given 1) and 2) why,why , why would you set about installing an expensive electronic sensor on the tie rod , which is just about the most debris hit, water soaked, vibration battered location on a car then plan for it to work at 100% perfection for a 15 year life that OEM'sare expected to design to?

What makes SBW so much better as to justify such a cost and reliability engineering challenge ?

Something that really irritates me (to be honest though, everything irritates me these days...) is half-asleep drivers at traffic lights. Whenever there's a lineup of cars at a red light you can bet that someone towards the front of the queue will be slow to take off when the lights turn green. So instead of say 15 or 20 cars passing through it's only 6 or 7. If all the cars could accelerate simultaneously I think it would make a massive improvement to traffic flow.

Something that really irritates me (to be honest though, everything irritates me these days...) is half-asleep drivers at traffic lights. Whenever there's a lineup of cars at a red light you can bet that someone towards the front of the queue will be slow to take off when the lights turn green. So instead of say 15 or 20 cars passing through it's only 6 or 7. If all the cars could accelerate simultaneously I think it would make a massive improvement to traffic flow.

Around here, honking is mandatory immediately after the light goes green. Even if you're 10th car in line.

At the end of my road, and the only way out into the Big Wide World, the traffic lights are green for less than 9 seconds. All it takes is the lead car to go throught the "Oh, they've gone green! Er, am I in neutral? Is this neutral, I think it is - left and up. No, back into neutral, can't be too careful - left, up, I think that's in - Oh, they've gone red!" routine, and you feel your life slipping away.

Something that really irritates me (to be honest though, everything irritates me these days...) is half-asleep drivers at traffic lights. Whenever there's a lineup of cars at a red light you can bet that someone towards the front of the queue will be slow to take off when the lights turn green. So instead of say 15 or 20 cars passing through it's only 6 or 7. If all the cars could accelerate simultaneously I think it would make a massive improvement to traffic flow.

What makes SBW so much better as to justify such a cost and reliability engineering challenge ?

packaging, crash, weight, gee-whiz factor, ability to do some seriously weird stuff. For instance by steering each wheel independently, well I don't know, but you could do some seriously odd things. But the main advanatage is that you no longer need a steering colum or rack, so the engine bay can suddeny be full of engine and batteries etc, instead of needing to leave long inconvenient packaging volumes for the intermediate shaft and rack. Also your steering wheel becomes part of your crash solution rather than being the main problem.

given 1) and 2) why,why , why would you set about installing an expensive electronic sensor on the tie rod , which is just about the most debris hit, water soaked, vibration battered location on a car then plan for it to work at 100% perfection for a 15 year life that OEM'sare expected to design to?

What makes SBW so much better as to justify such a cost and reliability engineering challenge ?

Many cars already have what are effectively SBW systems. Stability control systems use various combinations of ABS at each wheel, electronic throttle control, electronic diff control, and electronic control of dampeners to override driver inputs and stabilize the vehicle. Software, digital controls, solid state sensors and electronic systems operating at 100Hz or more are way more capable than any human.

The steering effect produced by these systems doesn't typically require a direct sensor feedback such as a strain gauge on the tie rods. Instead they make calculated decisions that rely on several indirect forms of feedback from sensors like 3 axis accelerometers or hall effect sensors on each wheel.

That seems like it's asking for trouble. There maybe a lot of situations where driving into the back of the car infront is desirable. When there are pedestrians nearby, oncoming traffic, driving near a ditch, tree, cliff on a bridge etc. Can the system detect and assess if swerving is safer than hitting the car infront?

But what if what looks like an empty stretch of road the car will swerve into is actually an active minefield? Humans would be able to read the yellow sign warning of the minefield in the left lane, but will computers have language recognition skills to realize it before they blow up the car in the avoidance maneuver?

The level of sophistication required for that system is approaching what is required for a fully driverless system. My guess is Nissan (and others) figure the market isn't ready for that yet and will only develop/offer what is palatable for now. Or could it be that Google have the jump in terms of patent protection?

With the electric power steering I honestly can not see any advantages of it, and is as known a whole lot of disadvantages.
A driver does need to know the conditions underneath him, damping it down is generally advantagous though a lot of cars with mechanical steering have either too much feedback, or often overdamped or slow steering.
Suspension design often comes into this too, a double wishbone is generally nicer and the cheaper strut is usually more nervous and twitchy. While these days none are bad some a mentally more demanding if not physically.
And in inclement conditions, broken up roads or loose surfaces feedback is essential.
The joke is so many cars have huge wheels, wide low profile tyres and then wonder about ride quality!!! With the huge amounts of steering feedback that comes from such dumb set ups. Manufacturers are making vehicles for best case scenario and most countrys are worst case these days. That is b efore we even talk about dirt where these stupid wheels are downright dangerous, an accident waiting too happen.
Then taking away the road feel is just another degree of stupidity. A mechanical system, correctly damped will have at least some feel, an electric motor seldom does, and must be far more prone to failure in adverse conditions too.

With the electric power steering I honestly can not see any advantages

Here ya go! You only have to look.

packaging, crash, weight, gee-whiz factor, ability to do some seriously weird stuff. For instance by steering each wheel independently, well I don't know, but you could do some seriously odd things. But the main advanatage is that you no longer need a steering colum or rack, so the engine bay can suddeny be full of engine and batteries etc, instead of needing to leave long inconvenient packaging volumes for the intermediate shaft and rack. Also your steering wheel becomes part of your crash solution rather than being the main problem.

reading the last part of your link brought one immediate feeling - 'would I be comfortable giving over control of a potential lethal machine and possibly also my life' , daily transport is so much part of our lives, not being in control and ultimately taking responsibility would be very difficult .

I can't even do fairground rides , but am quite happy being on the edge of the performance envelope and a potential major accident during a speed hillclimb - its about being in charge/control of ones life

reading the last part of your link brought one immediate feeling - 'would I be comfortable giving over control of a potential lethal machine and possibly also my life' , daily transport is so much part of our lives, not being in control and ultimately taking responsibility would be very difficult .

I can't even do fairground rides , but am quite happy being on the edge of the performance envelope and a potential major accident during a speed hillclimb - its about being in charge/control of ones life

'But only by a few measly seconds' How many seconds? Probably about 10, maybe more. Which says it all.Meaning the car is about as fast as any idiot driver,, and in many cases an idiot can be trained to drive far better. Sometimes!!

I have terrible habit of skim reading books I buy as presents so when I bought my son ( an avid " air rash investigators" fan) a copy of the story of the Quantas A380 flight engine failure by the Captain of the aircaft I skim read it.

Althought the events whereby the plane had an uncontained engine explosion are well known I had not realized just how badly damaged the plane was.

Many critical sensors and actuators were lost. So the Fly by wire computers were simply unable to operate properly even in back up to back up mode as they lacked enough sensor data .

The plane had four highly experienced pilots on the flight deck and it took all of them to understand what was wrong , and critically, what bad info. the computers were telling them.

At one point the systems clearly told them to pump fuel into the damaged wing. The captain called a flight crew "sense chack " and all four voted " NO WAY"

Obviously a car can stop easier than plane etc. but the next time anybody tells me computers can always fly a plane , or car, safer than an experienced pilot I'll point them at that book.

I have terrible habit of skim reading books I buy as presents so when I bought my son ( an avid " air rash investigators" fan) a copy of the story of the Quantas A380 flight engine failure by the Captain of the aircaft I skim read it.

Althought the events whereby the plane had an uncontained engine explosion are well known I had not realized just how badly damaged the plane was.

Many critical sensors and actuators were lost. So the Fly by wire computers were simply unable to operate properly even in back up to back up mode as they lacked enough sensor data .

The plane had four highly experienced pilots on the flight deck and it took all of them to understand what was wrong , and critically, what bad info. the computers were telling them.

At one point the systems clearly told them to pump fuel into the damaged wing. The captain called a flight crew "sense chack " and all four voted " NO WAY"

Obviously a car can stop easier than plane etc. but the next time anybody tells me computers can always fly a plane , or car, safer than an experienced pilot I'll point them at that book.

Once again "Four Corners" provides the definitive piece of investigative journalism.

Yes the plane would have crashed but for the skill of the humans in control. OTOH computers have made aviation much safer by reducing opportunities for human error. The same is already true in the automotive arena and will become increasing so - yes even to the point of autonomous control when it hits the market.

It's not a safety issue as much as a sales issue, everyone thinks they are an elite driver so people will tell themselves "it may be better than the average driver but not than I" and invent all sorts of fanciful rationalizations such as contrived highly unlikely hypotheticals they believe an "elite driver"-- e.g. themselves-- could do better than the automated driver. So even if the systems are significantly safer overall than real drivers, those drivers' hubris will prevent them accepting them as such.

It's not a safety issue as much as a sales issue, everyone thinks they are an elite driver so people will tell themselves "it may be better than the average driver but not than I" and invent all sorts of fanciful rationalizations such as contrived highly unlikely hypotheticals they believe an "elite driver"-- e.g. themselves-- could do better than the automated driver. So even if the systems are significantly safer overall than real drivers, those drivers' hubris will prevent them accepting them as such.

But everyone's wife doesn't think she's an 'elite' driver, so will be quite happy to be chauffeured around.........

It's got to be a load of fun to sit in a car that some chips are driving for you. Imagine the exhilaration! Boo yeah!

Yes, but safe & incident-free driving isn't really meant to be exhilarating. That should be saved for the race track or the rally stage. Sorry. boring, I know, but out there in the real world, that's how people think.

Yes, but safe & incident-free driving isn't really meant to be exhilarating. That should be saved for the race track or the rally stage. Sorry. boring, I know, but out there in the real world, that's how people think.

And its how they drive. When CANBUS was introducued we built some real time data loggers and recorded 7 million seconds of real driver usage. Apart from two seconds of data from Sydney at 0.8g braking there was no sign that anybody used more than 70% of the maximum capability of the vehicle in that time.

If you have one of those g analyst things, try and drive for 0.5g through 3 connected corners on public roads. I won't post bail for you, but I might send flowers if you end up in hospital.

I have terrible habit of skim reading books I buy as presents so when I bought my son ( an avid " air rash investigators" fan) a copy of the story of the Quantas A380 flight engine failure by the Captain of the aircaft I skim read it.

Althought the events whereby the plane had an uncontained engine explosion are well known I had not realized just how badly damaged the plane was.

Many critical sensors and actuators were lost. So the Fly by wire computers were simply unable to operate properly even in back up to back up mode as they lacked enough sensor data .

The plane had four highly experienced pilots on the flight deck and it took all of them to understand what was wrong , and critically, what bad info. the computers were telling them.

At one point the systems clearly told them to pump fuel into the damaged wing. The captain called a flight crew "sense chack " and all four voted " NO WAY"

Obviously a car can stop easier than plane etc. but the next time anybody tells me computers can always fly a plane , or car, safer than an experienced pilot I'll point them at that book.

"Always" is way too high of a standard. Any technological advancement will bring about new modes of failure that weren't present before. The decider is whether the new modes of failure bite less often than the old modes of failure they minimize.

In the meantime to fit that emergency brake system with radar to all cars would be a modest compromise I think, wouldn't that prevent most rear ending crashes?

Or create some? Perhaps drivers of such cars will become complacent resulting in a higher number of cars performing emergency stops . . . . . and the car behind may or may not be fitted with the system . . . . . . . just saying . . .

Or create some? Perhaps drivers of such cars will become complacent resulting in a higher number of cars performing emergency stops . . . . . and the car behind may or may not be fitted with the system . . . . . . . just saying . . .

That's a great argument for not introducing disc brakes and radial tires, both of which gave a step change in performance compared with the preceeding system.

I suggest you game out the variosu combinations of Radar assisted brakes and drivers too close to car in front, RAB still results in a net reduction in accidents.1)car 1 stops suddenly

I also with magoo welcome our new masters,the self driving cars of the future.I bow down before them and trust in their peerless wisdom.
I'll be buying the one which fills in the insurance form for you.In fact we won't need insurance will we,in
this brave new world of perfectly driven cars ?

I don't now where the "google must do 300 million miles without a fatality "comes from , but it does illustrate the problems with certification that driverless cars will face before becoming proven to be safe.

Lets just suppose 300 M mile is right (?). Its pretty hard to do more than 300 miles per day in representative trafific ( ten hrs at 30 mph suburban average ) because driving it round at night isnt a real test. So 360*300 = 108K miles per year. So you for our 300M miles validation you need about 500 cars for 6 years.

Thats not imposible or unaffordable but it illustrates that what Google are doing is really just another "proof of concept", not an FAA type certification process.

The way I read the article, someone's just saying that with the stat of 1.11 fatalities per 100 million miles, 300 million miles is the sample size needed to be able to make a claim about that stat. It says nothing about certification or Google's intentions.

I don't think a target of one fatality per 300 M miles for a driverless car is at all unreasonable.

The Uk is reported at 5.9 fatalities per Billion vehicle Km versus 8.5 per Billion for the USA. There are lots of reasons for the difference but the Uk number is not a bad US goal . so the current US 1.3 per 100 M miles would be about one fatality per 110 milion miles.

It seems hardly worth doing driverless cars unless a significant reduction in road deaths is a result ( and that is Googles awoved reason for persuing driverless cars).

So if you say other measures could get the US to the Uk level then one death per 110M miles is acheivable without driverless cars so a goal of one death per 300M seems no more than a modest target to me.

Also current actual death rates have, sadly, a vast actual database. The driverless rate wil be hypothetical for a long time as milage builds up so aiming for less than one per 300 M would be risking driverless cars being LESS safe in practice.

Regardles of the sort of goals the enginers would set any outcome below 300M is likely to be legally and socially un-acceptable in today's blame society in the west.

There are lots of benefits to autonomous cars besides safety: -Increased access for the disabled-More possibility for car-sharing, which means fewer cars, more parking, and money saved-Increased productivity

All they have to do is show that the accident, injury, and fatality rates are no worse than human drivers and it's a win. As you point out, even if a car is perfectly driven other drivers will still run into it.

Regardles of the sort of goals the enginers would set any outcome below 300M is likely to be legally and socially un-acceptable in today's blame society in the west.

A reduction in fatalities isn't the only benefit though. How about the benefit through a (presumably) massive reduction in accidents that don't result in fatalities. Medical fees, crash repair fees, insurance fees, reduction in sick leave, etc, etc, all that broken window economic activity that could be redirected elsewhere.

Presumably the fatal accident rate could actually be worse and still result in a net benefit to society but then you'd be putting a price on someone's life, which for some reason people feel uncomfortable about.